There are various mechanisms by which the liquid medicine can be aerosolised. Depending on these mechanisms, the nebulisers are categorised into various types (elaborated below).

Mechanism
Jet nebulisers use pressurised gas/air to draw the liquid medication from the nebuliser cup through a thin capillary. The pressurised air or gas is provided by the compressor. The liquid medication is converted into an aerosol or mist comprising small and large particles. Smaller particles are inhaled, whilethe larger particles hit the inside wall of the medication cup and enter back into the medication cup/chamber.

Advantages

• Any type of liquid medicine can be nebulised.
• Jet nebulisers are less expensive.

Limitations

• Less portable.
• Assembling the nebuliser can be difficult for some patients who suffer from physical and cognitive impairment.
• Aerosol output is not consistent.

Mechanism
Mesh nebulisers use a mesh or aperture plate to generate the aerosol or mist.

Advantages

• Has improved and consistent aerosol-generating efficiency as compared to jet nebulisers.
• Nebulisation can be achieved using a low medication volume as compared to jet nebulisers.
• Small size, lightweight, and battery-operated system makes it easily portable and handy.

Limitations

• Most mesh nebulisers cannot be used to deliversuspensions (these do not flow easily and, so, can clog the mesh pores).
• Can be difficult to clean.
• More expensive than jet nebulisers.

Mechanism
Ultrasonic nebulisers use high-frequency vibrations generated by a piezoelectric crystal to produce the aerosol.

Advantages

• Used to deliver inhaled medicines and saline for sputum induction (a procedure to collect respiratory secretions).

Limitations

• Cannot be used to deliver viscous solutions or suspensions.
• Has a large residual volume (leftover medicine that cannot be nebulised, resulting in medicine wastage).
• Generates heat when in use; hence, not suitable for heat-sensitive material such as proteins and suspensions.

Mechanism
Smart nebulisers have an inbuilt automatic sensor that senses your breathing and determines when the aerosol should be delivered. Some smart nebulisers also keep a log of the usage, which helps in patient adherence to therapy.

Advantages

• Reduces loss of medication into the surroundings.
• Reduces variability in medicine delivery.
• Improves patient adherence to the treatment regimen.
• Better control over the delivery of expensive medicines (such as proteins).

Limitations

• More expensive than other nebulisers.

It is recommended that you also refer to and follow the instruction manual of your nebuliser system as there might be some differences in the steps involved.

Given below are the steps for cleaning and disinfecting jet nebulisers. However, it is recommended that the user also refer to and follow the steps detailed in the manufacturer’s information booklet.

Nebulisers should be cleaned after each treatment and also disinfected daily to prevent the risk of infection. Here are some tips that can help you with cleaning and maintaining the nebuliser:

Cleaning

1. Turn off the power switch and unplug the power cord.
2. Disconnect the tubing from the air outlet on the compressor.
3. Detach the face mask or mouthpiece from the medication cup. Remove the cap of the medication cup.
4. Wash all the accessories (except the tubing) in warm water or a mild detergent solution. Remove any detergent residue by rinsing the accessories in warm water and allow them to air-dry.
5. Wipe the outer surface of the tubing regularly. If any liquid droplets are noticed in the tubing, connect the tubing to the compressor air outlet, detach the medication cup, switch on the compressor and blow air through the tubing for a few seconds to dry it out.
6. Do not towel-dry the accessories. The accessories must be air-dried in a clean place.

The cleaning should be done after every use and disinfection should be done once daily.

Remember to clean and disinfect the nebuliser accessories daily.

1. Disinfection of the device needs to be done once in 24 hours. It can be done at home by using a disinfecting agent such as rubbing alcohol (70% isopropanol). In clinics or hospitals, another option that can be used is 3% hydrogen peroxide. If rubbing alcohol is used, immerse the accessories for 5 minutes; if using hydrogen peroxide, immerse the accessories for 30 minutes. An electric steam steriliser (baby bottle steriliser) can also be used. Simply boiling the accessories in clean water for 5 minutes can also effectively disinfect them.
2. After disinfecting the accessories, rinse them thoroughly with water. If this is not possible, rinse them with filtered or tap water. Then keep them in a clean place to air-dry.

Nebuliser accessories such as a face mask, mouthpiece, baffle, medication cup and its cap (excluding the tubing) should be cleaned after every use and disinfected daily.

Care of the nebuliser

1. When the compressor is not in use, cover it with a clean cloth and keep it in a safe, dry and secure place.
2. Do not keep the air compressor on the floor either for storage or for treatment.
3. Check the filter in the air compressor regularly. The filter in the compressor filters the surrounding air, which is pumped with pressure by the compressor into the tubing. Replace it according to the directions given by the equipment supplier. This filter is disposable and should not be washed and reused and, generally, spare filters are provided with the nebulisation kit.
4. All the accessories required for nebuliser therapy can be obtained from the equipment supplier.
5. Store the medications for nebulisation in a cool, dry place as per the instructions on the pack.
6. Check the medications frequently for any change in colour or turbidity or crystal formation. If present, throw them away and replace them with new ones.

For your convenience, always keep a backup for the medication cup, tubing, compressor air filters, face mask or mouthpiece, and medications. Also keep a spare compressor as a backup (useful in case of a compressor breakdown), which can be availed of from the equipment supplier.

Follow the manufacturer’s instructions while cleaning your nebuliser.

As with any other machine, a nebuliser also needs to be maintained well for optimum performance. It is essential to clean and disinfect the nebulisers and its accessories to prevent bacterial growth and infection. Moreover, replacement of the parts is also essential when they have worn out.

Key points to remember [related to Jet Nebuliser]

1. The compressor should be regularly wiped from outside with a dry cloth. The compressor body should never be opened. The disassembly and internal repair of the compressor should be done by the technician and not by the user.
2. The medication cup should be cleaned after each procedure as per the cleaning instructions provided in the device manual.
3. The tubing should be checked regularly to see if any liquid droplets are present and replaced every 3 months. If any liquid has entered the tubing, blow air into it through the compressor (without the medication cup attached); this will fully expel any liquid droplets.
4. Face mask and mouthpiece should be cleaned after each nebulisation and disinfected daily and replaced every 3 months.
5. The filter is disposable. It should be replaced when it discolours, i.e. colour changes from white to yellow. It should not be reused or washed or replaced with any other material.

Managing breakdown of the nebuliser

• It is better to keep an alternate nebulisation kit handy if the nebuliser is being regularly used.
• Keep all information about the nebuliser being used within reach so that a replacement can be immediately procured.
• Contact your doctor or healthcare specialist to get help in case of an emergency.
• Keep all information handy regarding the chemist or medical store that can supply a nebuliser unit quickly in case it is needed.